In winter, the quality of green grass management directly affects the quality of the lawn in the next year. How to make green grass safely overwinter and lay a solid foundation for the next spring greening is the top priority of winter management. This article provides several suggestions for winter green overwintering management for readers’ reference.
The research and progress of lawn management have made a great leap in the maintenance of golf courses. The use of various advanced technologies has improved the management of lawns to a higher quality than in the past. This is because advanced technology can provide “degree control” for maintenance and can nip problems in the bud. However, plans often cannot keep up with changes. It is unrealistic to master all relevant variables of the golf course, especially for golf courses in the northern United States that suffer from “winter injury”. Sometimes nature lets us know how much control we have (it can be said that there is very little). In the past 10 years, many golf courses in the northern United States have suffered huge lawn losses due to the treatment of ice and snow. They usually use direct low-temperature killing, top hydration or wind drying, and some even use methods to “suffocate” the grass.
Although some agronomic knowledge can be used to prevent lawn diseases in winter, managers do not have complete control. What lawn managers can do is to control certain aspects of lawn health, which can be grass growth strategies, modify grass seed selection plans, decide on the use of plant protection agents, enhance drainage facilities, change surface drainage patterns, and more importantly, adjust the growth environment of grass by planting trees to restrict airflow. The following will discuss some measures that are being used to minimize the damage to lawns during winter.
A. Hardening process
In autumn and early winter, plants resist low temperature freezing by continuously adding considerable concentrations of carbohydrates and other nutrient-rich solutes to cells (there is a large central vacuole in plant cells, which contains a large amount of water, accounting for more than 85% of the fresh weight of the plant body. Once the water in the cell freezes, it will destroy the cell structure and cause cell death. Therefore, in order to successfully survive the winter, it is necessary to prevent freezing in the cell. One way is to synthesize more soluble sugars and amino acids to increase the solutes in the vacuole and lower the freezing point. However, lowering the freezing point in this way can only work above -5°C at most: below -5°C, it needs to rely on macromolecules such as proteins to work). For lawn plants to reach full hardening, they must go through a freezing phase of at least one month, but in the spring, the hardening process of plants is the opposite (the carbohydrates stored in the tissue cells must be quickly consumed and turn green). In the process of thawing, the damaged cells are exposed to low temperatures again, and their internal substances are extremely susceptible to low temperatures. If the lawn grass tissue cells are thawed and encounter low temperatures, the thawed cells will freeze again, and thaw again as the temperature rises. If this is repeated, the lawn will suffer serious damage. Investigations and studies have found that susceptible unhardened bluegrass species react to temperature fluctuations. Unhardened grass species can tolerate 23-28 degrees Fahrenheit, while fully hardened grass species can survive at minus 1-25 degrees Fahrenheit. By comparison, researchers found that the lowest cold-resistant temperature of creeping bentgrass can reach minus 40 degrees Fahrenheit.
Bluegrass can quickly “thaw” after 48 hours at 45 degrees Fahrenheit. In parts of the mid-Atlantic coast, temperatures often fluctuate in a very short period of time. For example, the early winter of 2003-2004 was the golden period for plant hardening. The temperature in the Pittsburgh area reached 61 degrees Fahrenheit on January 3, and the temperature dropped to below zero just 7 days later. Under such temperature fluctuations, even if you are prepared and take good protective measures, it can become “in vain” in an instant. For areas with unpredictable temperature changes, turf grass need to seriously study how to improve the “vitality” of turf in bad weather, especially for grass species that have to undergo rapid hardening and thawing cycles.
Post time: Dec-19-2024